Experimental Study of Fiber Orientation Effect on Frictional Material Properties and Tribology Performance

2020 ◽  
Vol 304 ◽  
pp. 25-32
Author(s):  
Maitri Kamonrattanapisud ◽  
Karuna Tuchinda
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Material Properties ◽  
Fiber Orientation ◽  
Orientation Effect ◽  
Fiber Direction ◽  
Surface Wear ◽  
Frictional Material ◽  
Tribology Performance

The objective of this work is to study the fiber orientation effect on frictional material properties and tribology performance. Effects of orientation on hardness, maximum load capacity under bending, the friction coefficient and surface wear of the composites were investigated. In this research, 3D printing technique was used to create workpieces in order to control fiber arrangement which is random, 0, 45, and 90 degrees. The results suggested that the fiber direction insignificantly affects material hardness with all specimen showing similar value of average hardness of approx. 90 HRC. However, the fiber orientation had a strong influence on material bending strength. The specimen with forced fiber orientation showed lower bending resistance compared to that with random fiber orientation. This may be caused by the non-uniform distribution of fiber which could promote fracture initiation site in some area with low fiber density. The coefficient of friction of the composite material was found to strongly related to it wear behavior, i.e. higher wear rate results in higher value of friction coefficient. The wear resistance was found to be controlled by both the fiber direction and fiber interface. With fiber oriented at 90 degree to sliding direction, higher coefficient was observed. However, as surface wear took place, the effect of wear debris results in an increase in friction coefficient. For 3D printed specimen, wear was increased with fiber interface density resulting in higher wear rate of specimen with 0-degree fiber orientation compared to those with 45-and 90-degree orientation during. Hence, the specimen with 0 degree fiber direction showed similar value of coefficient of friction to those with random and 90 degree fiber orientation.

Surface Wear Anisotropy in AlSi10Mg Alloy Sample Fabricated by Selective Laser Melting: Effect of Hatch Style, Scan Rotation and Use of Fresh and Recycled Powder

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Ashish Kumar Mishra ◽  
Ram Krishna Upadhyay ◽  
Arvind Kumar
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Selective Laser Melting ◽  
Wear Behavior ◽  
Alloy Sample ◽  
Surface Wear ◽  
Wear Properties ◽  
Laser Melting ◽  
Pattern Size ◽  
Scan Pattern

Abstract Additive manufacturing (AM) has witnessed substantial growth in recent years due to its excellent manufacturing capabilities and innovative production methodologies. However, the mechanical suitability aspect in terms of material wear has not received much attention yet and needs rigorous assessment. This study investigates the wear anisotropy in an AlSi10Mg alloy sample fabricated by selective laser melting (SLM) technique. Different scanning strategies encompassing the island and the continuous scanning patterns were used in sample manufacturing. The effects of the scanning vector orientation, design pattern, and the island pattern size on the mechanical wear and wear anisotropy have been analyzed in detail. The study also focused upon a comparative investigation of the wear properties at the top and the side surfaces to understand the wear anisotropy in different directions. The samples are fabricated both by the fresh and the recycled powder and the role of powder state is described. The ball-on-disk test is performed to simulate the similar contact applications for marine/automotive components such as bearings. Bearing steel balls are used as a standard sliding counterpart material to investigate the wear properties. The wear microstructure is analyzed by scanning electron microscopy. Overall, the island strategy with 2 mm hatch style and 45 deg scan rotation have achieved better wear resistance and friction coefficient compared with the continuous hatch style. The wear behavior is found to be anisotropic. The Raman spectra validate the presence of silicon and carbon particles on the wear track, which have a significant effect on the tribological properties. The type of particles present in the sliding zone characterizes different wear stages. Wear mechanism is described by considering four parameters, namely, scan pattern, scan vector rotation, type of powder, and the wear measurement direction. Results show that the surface wear rate of samples made by the fresh powder is lower than the recycled powder. However, samples of the recycled powder have friction modifier characteristics. The best wear rate and friction coefficient values are obtained with the island strategy (2 mm hatch, 45 deg scan rotation) in the side plane and are 3.76 × 10−6 mm3/N m, 0.0781, respectively.

scholarly journals Tribological Properties of PVD Ti/C-N Nanocoatnigs

2017 ◽  
Vol 54 (2) ◽  
pp. 64-71
Author(s):  
A. Leitans ◽  
J. Lungevics ◽  
J. Rudzitis ◽  
A. Filipovs
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Roughness Parameter ◽  
Surface Wear ◽  
Roughness Parameters ◽  
Coating Deposition ◽  
2D And 3D

Abstract The present paper discusses and analyses tribological properties of various coatings that increase surface wear resistance. Four Ti/C-N nanocoatings with different coating deposition settings are analysed. Tribological and metrological tests on the samples are performed: 2D and 3D parameters of the surface roughness are measured with modern profilometer, and friction coefficient is measured with CSM Instruments equipment. Roughness parameters Ra, Sa, Sz, Str, Sds, Vmp, Vmc and friction coefficient at 6N load are determined during the experiment. The examined samples have many pores, which is the main reason for relatively large values of roughness parameter. A slight wear is identified in all four samples as well; its friction coefficient values range from 0,.21 to 0.29. Wear rate values are not calculated for the investigated coatings, as no expressed tribotracks are detected on the coating surface.

The influence of laser surface texture on the tribological properties of friction layer materials in ultrasound motors

2021 ◽  
pp. 135065012110527
Author(s):  
Xijun Hua ◽  
Julius Caesar Puoza ◽  
Peiyun Zhang
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Dry Friction ◽  
Friction And Wear ◽  
Ultrasonic Motor ◽  
Area Ratio ◽  
Ultrasonic Motors ◽  
Increase Rate

Ultrasonic motors are typically driven by the dry friction force between the rotor and the stator; the friction pairs’ high friction coefficient and low wear rate are two essential elements for improving the operational stability with longer service life. In this research article, high-precision microgroove arrays were manufactured on the surfaces of the stator and rotor of the TRUSM60 ultrasonic motor using laser machining. Dry friction and wear tests between the stator and the rotor were carried out with pin-on-disc using HSR-2M high-speed reciprocating friction and wear tester to determine the tribological properties of the ultrasonic motor. According to a different distribution of microgrooves on the two contact surfaces, the influence of smooth surface, single-sided texture, and double-sided texture on the friction pair's friction performance were discussed. The results show that the textured surface can substantially increase the coefficient of friction of the contact surface and reduce the rate of wear. The one-sided textured phosphor bronze surface with a microgroove width of 200μm and an area ratio of 20% had the highest coefficient of friction of 0.334 and a friction increase rate of 36.3%. Similarly, the single-sided textured Polyimide surface attained the highest friction coefficient of 0.355 and friction increase rate of 44.9% when the groove width is 150μm and the area ratio is 30%. A higher friction coefficient of the double-sided texture can be obtained through reasonable parameter configuration than the single-sided texture. The included angle of 0° between the two textured surfaces produced the highest friction coefficient of 0.368 and the wear rate of the phosphor bronze and polyimide surfaces were 2.01 × 10−4 mm3/N-m and 1.949 × 10−3 mm3/N-m, respectively. The result provides an essential benchmark for enhancing the tribological performance of ultrasonic motors and increasing the output torque.

Tribological properties of pyrolytic carbon in high-speed tests

2020 ◽  
pp. 71-75
Author(s):  
V. A. Khorev ◽  
V. I. Rumyantsev ◽  
G. A. Ponomarenko ◽  
A. S. Osmakov ◽  
V. N. Fischev
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
High Speed ◽  
Tribological Behavior ◽  
Pyrolytic Carbon ◽  
Extreme Conditions ◽  
Friction Units ◽  
The Difference

The friction units of modern power turbines require the use of special materials with a stable and low coefficient of friction in extreme conditions. The most successfully used for these purposes are antifriction carbon-graphite materials, in particular isotropic pyrolytic carbon. It is established that isotropic pyrolytic carbon has a lower friction coefficient and wear rate than ATG-S antifriction graphite. Based on the analysis of the microstructure and fractograms of wear traces, it was suggested that the difference in the tribological behavior of materials is caused by various mechanisms of material destruction. It is also shown that isotropic pyrolytic carbon tends to decrease the wear rate and friction coefficient with increasing density. Ill. 7. Ref. 10. Tab. 1.

scholarly journals Modeling of fatigue damage accumulation in multiple contact of pre-stressed bodies in the presence of wear

2020 ◽  
pp. 78-88
Author(s):  
Ирина Георгиевна Горячева ◽  
Елена Владимировна Торская
Keyword(s):  
Shear Stress ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Residual Stresses ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Rolling Contact ◽  
Surface Wear ◽  
Fatigue Damage Accumulation ◽  
Relative Slippage

Рассматривается влияние остаточных напряжений, формирующихся при различных видах поверхностной обработки элементов пар трения, на скорость накопления контактно-усталостных повреждений, возникающих при циклическом нагружении поверхностей взаимодействующих тел в условиях трения качения при наличии поверхностного изнашивания. Исследовано влияние относительного проскальзывания, коэффициента трения скольжения, величины остаточных напряжений на распределение амплитудных значений максимальных касательных напряжений. Полученные результаты использованы для анализа влияния поля остаточных напряжений и скорости поверхностного изнашивания на процесс накопления контактно-усталостных повреждений. Residual stresses are formed during various types of surface treatment of elements of friction pairs. The effect of the residual stresses on the rate of fatigue damage accumulation is considered for the case of cyclic rolling contact in the presence of surface wear. The effect of relative slippage, friction coefficient, and residual stresses on the distribution of the amplitude values of the principal shear stress is studied. The results are used to analyze the effect of the residual stresses and the surface wear rate on the fatigue damage accumulation.

Studies on Dynamic Tribology Properties of Friction Materials by Using an Approximate In Situ Observation for Worn Surfaces

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Weitao Sun ◽  
Wenlong Zhou ◽  
Jianfa Liu ◽  
Xuesong Fu ◽  
Guoqing Chen ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Friction Material ◽  
In Situ Observation ◽  
Friction Materials ◽  
In Situ Method ◽  
Friction Tester ◽  
Tribology Performance ◽  
Worn Surfaces

This paper primarily focused on the dynamic tribology properties of one certain nonasbestos organic (NAO) friction material by using an approximate in situ method. This study was performed through a pad-on-disk type friction tester under different temperature conditions. Results showed that temperature has a significant effect on the dynamic tribology performance. At 100 °C, friction coefficient and wear rate after the running-in stage varied little with time. At 250 °C, friction coefficient after the running-in stage increased gradually and then tended to be stable, while wear rate decreased gradually. From 100 to 350 °C, friction coefficient increased first as a function of temperature, but decreased sharply when the temperature was over 250 °C. Simultaneously, wear rate also increased sharply over 250 °C. Additionally, three dynamic evolution models of worn surfaces corresponding to different cases were established.

Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Die Casting ◽  
Casting Machine ◽  
Injection Pressure ◽  
Casting Process ◽  
Matrix Alloy ◽  
Content Type ◽  
The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication

2021 ◽  
pp. 135065012110334
Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Surface Texture ◽  
Diamond Film ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Water Contact ◽  
Texture Density ◽  
Short Run

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.

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